X-ray apparatus



June 1949 E. B. GRAVES 2,203,2ZQ

X-RAY APPARATUS Original Filed Oct. 28, 1937 2 Sheets-Sheet l F i f INVENTOR w EDWARD B. GRAVES wfiz' w ATTO R N EYS June 4, 194% & @RAVES 2,2@3,279

X-RAY APPARATUS Original Filfid 0C1. 28, 1937 2 Sheets-Sheet 2 FIG-5 20 INVENTOR EDWARD B. GRAVES ATTO R N EYS Patented June 4, 1940 UNITED STATES PATENT OFFICE X-RAY APPARATUS Edward B. Graves, South Euclid, Ohio, asslgnor to Picker X-Ray Corporation Waite Manufacturing Division, Inc., Cleveland, Ohio, a corporation of Ohio 3 Claims.

This invention relates to transformer apparatus for selectively operating, and controlling, a pair or more of X-ray tubes. Apparatus employing such tubes, indicating their manner of em ployment, is more fully disclosed in Patent No. 2,117,660, for X-ray apparatus, granted May 1'7, 1938 to Edwin R. Goldfield, wherein it will be seen that a single transformer unit is provided for selective operation of either of two tubes.

This application is a division of my copending application Serial No. 171,503, filed October 28, 1937, which resulted in Patent No. 2,137,647, for X-ray apparatus, granted November 22, 1938.

The present invention has for its general object the provision of a transformer unit for selective operation of any of a plurality of X-ray tubes, which unit shall be of minimum size, with its parts compactly arranged and, if desired, to provide a long narrow form.

Another object of the invention is to serve X-ray tubes of the type having a plurality of filaments as for double focus, and provide for selective energization of the filaments of the selected tubes.

The invention contemplates immersion of the elements of the transformer unit in a single body of fiuid dielectricsuch as oil, housed in a single container, and another particular object of the invention is to provide novel means for conmeeting the transformer unit to the tube to be served. Such means includes a novel type of high tension terminal carrying contactors submerged within the dielectric of the transformer unit and making dry connection with high tension cables leading to the tubes as will appear.

The exact nature of the invention together with further objects and advantages thereof will be apparent from the following description taken in connection with the accompanying drawings, in which Figs. 1 and 2 are plan and side elevation views respectively, of parts of the transformer unit, as with the near container sides removed, and showing the relative disposition of the parts; Fig. 3 is a diagrammatic view showing the circuits by which the parts function to serve the X-ray tubes; Fig. 4 is an enlarged section as in the plane of line 4-4, Figs. 1 and 2, showing a pair of high tension terminals with the switch parts carried thereby; and Fig. 5 is a further enlarged sectional elevation showing further details at one of the terminals.

With reference now to the drawings, 1 is a transformer unit container, housing a high tension transformer l0, high tension rectifying valve tubes l I, a filament transformer l2 for each valve tube and a pair of X-ray tube filament transformers I3, l3.

Physically, these parts are disposed within the container l as indicated in Figs. 1 and 2, the high tension transformer ill in the middle, two valve tubes H on either side of the transformer, the filament transformers l2 beyond their tubes and thereadjacent, and the X-ray tube filament transformers I3 above transformers 12, it being understood that these parts are surrounded by fiuid dielectric which substantially fills the container I, Preferably the top wall of the container is provided with removable closures Ia, one for each valve tube providing individual removal of these tubes for replacement.

The transformer unit is provided at each end with a set of terminals, one for each X-ray tube to be served, so that for each X-ray tube there are a pair of terminals, one at each end of the transformer unit.

In the drawings for simplicity'but two X-ray tubes A and B are illustrated as to be served, so that there are but two terminals each generally indicated at 2 at the left end of the unit and correspondingly two terminals each generally indicated at 3 at the right end.

Electrically the parts within the container I are interconnected as indicated in Fig. 3, served by lines L1 to L6 leading from a suitable control unit not shown but well known in the art, to the transformer unit. Of these lines L1 and L2 selectively energize the primary windings of either of the X-ray tube filament transformers l3, l3 by manipulation of switch 5, lines L3 and L4 coincidentally control the filament transformers 12 of all four valve tubes II, and lines L5 and L6 control the high tension transformer l0.

Each X-ray tube A, B, having two filaments as indicated, three connections are necessary at' the filament end of the tube for selective energization of its filaments; a single connection only being sufficient for its anode end.

The two terminals 2, one for each X-ray tube, which terminals serve the filament or cathode ends of the tubes, both include switch means for selecting between the X-ray tubes and make connection with multi-conductor shockproof cables A, B, as indicated in Figs. 4 and 5.

Each terminal comprises a bushing 20 of insulating material having a flange 2| for its securement against the top wall of the container I and recessed to provide a socket 22 preferably extending below the level of the dielectric within the container. Each bushing 20 extends above the container as shown at 20a in Fig. 2. The portion above the container embraces the sleeve 2 3 within the collar 25 and provides insulation about the cable. As illustrated in Figs. 4 and 5, three switch contactors 2a, 2b and 2c are mounted in aligned relation along the bushing, at the bottom end of the bushing, and correspondingly the base of the socket 22 is provided with three cable centactors 2a., 2b, 20'. These cable contactors are arranged concentrically with respect to the bushing 20, the contactor 2a being centrally located and the other contactors 2b and 20 being annular thereabout and also preferably slightly spaced longitudinally. The switch contactors are insulated from each other by cylindrical elements and the cable contactors are insulated from each other by the cylindrical and conical elements indicated, these latter insulating elements extending upwardly into the socket 222 between their contactorsall as illustrated in Fig. 5. Also as illustrated, each switch contactor has electrical connection with its corresponding one of the cable contactors. As here shown the switch contactor 20 has connection with its cable contactor 20' by conductor 20'', the switch contactor 2b has connection with its cable contactor 2b by conductor 2b", and the switch contactor 2a has direct connection with its cable contactor 2a, the latter extending downwardly in the form of a bolt as illustrated.

While 2a might be a bolt with a suitably shaped head, the actual parts shown comprise a conical nut threaded on the upper end of the bolt. It will be noted that the parts 2a, 2b, and 2c and the insulators between them are nested so that a threaded nut outside the bushing wall holds all of these parts in position firmly assembled on the central bolt. All of the conical and threaded parts are sealed bya compound which prevents entrance of oil into the internal socket of the bushing 2b.

The three-conductor shockproof cable A corresponding to the terminal parts just described, is arranged at its end as illustrated in Fig. 5 with three concentric helical contactor springs 23a, 23b, 230. Each of these springs is insulated from the others by the stepped and threaded insulating element 33 but each has electrical connection with one of the cable conductors by the wiring indicated, in drilled passages in the element, each spring being retained upon the element by the threads indicated.

The diameters of the contactor springs are such that when the end of the cable A is thrust into the socket 22 of the bushing 2@, each of its contactor springs 23a, 23b and 230 will make contact with its corresponding contactor 2a, 2b, 2c of the bushing, and thus establish separate connection with its corresponding switch contactor 2a, 2b, 2c.

The cable end part is maintained straight and aligned within the socket 22 of the bushing, so as to align the contactors, by a sleeve 2% of insulating material. A collar 25, about the sleeve, is secured on the top of the container l by any suitable means; and the cable is secured within the collar against endwise removal, by annular metal bushing 26, the arrangement permitting, however, rotation of the cable end about its axis, it being appreciated that such shockproof high tension cable is substantially stiff. Obviously the arrangement described and particularly the provision of freedom of the cable for adjustment about its axis, eliminates twisting of the cable and consequent bends and strains upon the cable at points removed from the transformer unit.

aaoame It will be understood that when the parts are fully assembled the cable and the sleeve 24 move down from the position of Fig. 5 into the bushing 20 so that the coil springs 23a, 23b, and 230 are compressed and make firm contact with the annular contactors 2a., 2b and 20' respectively.

As indicated in Figs. 1 to 4, the two terminals 2 are so disposed that their two sets of switch contactors 2a, 2b, 2c, face each other, with the two contactors 2a in the same plane and so on. Multi-pole multi-throw switch means is provided for selectively energizing either set of contactors from the current-producing means within the container l, for energizing the filament end of the selected X-ray tube. Such means is here shown as a series of contactors 21 connected in the circuit as indicated in Fig. 3 and mounted for movement between the sets of contactors 2a, 2b, 20, on the two terminals 2.

The multi-pole selector switch just described, is actuated by a controller 28 on the outside of the container 0 through the linkage including crank members 28a at the movable switch parts and at the controller as conventionally indicated in Figs. 2 and 3.

The other pair of terminal units 3 carry current only to the anodes of the tubes A and B and therefore need only have one contactor each. Otherwise they are generally similar to the terminals 2 hereinbefore described, and a single-pole multi-throw switch 30 is arranged to selectively connect either terminal 3 to the high tension out put of the transformer means, this switch 30 being so connected to the controller 28 as to be moved thereby in unison with the other, multipole, switch above described.

Consequently the arrangement is such that by operation of the controller 28 either X-ray tube A or B may have complete operative high tension connections established from the transformer unit.

Either X-ray tube being so connected, the low tension switch 5 permits selection between the filaments of that tube, for its desired focus.

What I claim is:

l. A terminal unit for the purpose described, comprising a generally cylindrical insulating bushing adapted to be mounted in a wall of a container and having an end part extending substantially within the container, a plurality of switch contactors mounted on said bushing end part, in spaced relation along the bushing and in insulated relation from each other, said bushing having a hollow socket extending centrally adjacent said contactors, said terminal unit having a plurality of cable contactors presented endwise at the base of and within said socket and in concentric relation with each other, and having means connecting each of said cable contactors with one of said switch contactors.

2. Cooperative shockproof cable and receptacle 7 connecting means for high tension X-ray appathat pair when another pair arein contact, the F several outer helical springs surrounding the inner springs.

3. A terminal unit providing a separable connection between a stiif high tension cable having a plurality of conductors and oil-immersed switch lationship with said cable contactors by insertion of said cable into said cavity, and a plurality of switch contactors carried by said bushing end part externally thereof and each electrically connected respectively with one of said coacting contactors within said cavity, the contactors carried by the bushing being arranged in nested relationship, threaded means clamping said nested contactors to said bushing end part, and means sealing said nested contactors against entrance 1 of oil into said bushing socket.

EDWARD B. GRAVES. 

